Previously, some venture capitalists thought an hour's drive was a long way to go for a board meeting, but the trend of only investing locally is changing, said Bill Green, managing director of VantagePoint Venture Partners.

"In this sector, very different trend lines are developing," he said.

He characterized the trend of paying attention only to local developments as "myopia" and said investors who did so could be blindsided by developments around the world.

One example might be Brazil.

Carlos Rodrigo Opice Leão, director of business development at Brenco, which makes ethanol from sugar, said 90 percent of the cars sold in Brazil today already are flex-fuel cars.

"It's already there; it's a reality," he said, adding that the cars are coming from General Motors, Volkswagen, Honda, Toyota and Mitsubishi. "Ethanol from sugar cane is competitive with gasoline today."

Only about 15 million acres are used to grow sugar cane in Brazil today, with about half of that being used for ethanol production, leaving plenty of opportunity for growth, he said.

Panelists also indicated that more insight into China could pay off.

Michael Goguen, a partner at Sequoia Capital, said China could become a major technology consumer. "China looks like a fascinating opportunity for us," he said.

While he said he doesn't yet have a sense of the technologies coming from China, he views the country as a great place to test some of Sequoia's portfolio companies' new technologies.

On a different panel, Jennifer Fonstad, a managing director at Draper Fisher Jurvetson, said she thinks China will be a greentech leader in as little as five years, possibly ranking even above the United States.

She thinks the Olympics will be "a seminal moment for officials in Beijing, because they will start to see what it means to have clean air in their own city," she said.

"The challenge is to match production costs to the market," or to find locations with both low production costs and proximity to major potential customers, he said.

But VCs looking to invest globally do face some challenges, among those understanding the different laws that impact green technologies in different countries, as well as the different languages, said Scott MacDonald, a partner at Emerald Technology Ventures.

"The challenges of geography are great," he said. "An investment in Silicon Valley is not the same as an investment in Stuttgart."

For one thing, people in Silicon Valley understand how to take technologies from a garage or basement into a viable business, but that entrepreneurial spirit and experience is not as easy to find in Europe, he said.

"We want to figure out how to cut and paste Silicon Valley into other jurisdictions," MacDonald said.

While Europe might have the biggest market, risk-taking is not as big a part of its culture, panelists suggested.

"In Europe, while there are some great things, if we offer people stock options or a turkey [for the holidays], many people would take the turkey," Green said. "They don't have the Silicon Valley DNA."

Still, Green said, the solution is not to move entrepreneurs to the market. Instead, more entrepreneurial training is needed because, in order to grow large, companies will need to do business in multiple countries.

Because customers are considering competing technologies worldwide, MacDonald said VCs also need to take a global view.

"We need to invest in the best technology for the best price with the best team," he said, "regardless of where it occurs."